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1.
Top Antivir Med ; 32(2): 411-419, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-39141919

RESUMEN

Vaccinations are an important part of primary care for people with HIV (PWH) and can protect against viral hepatitis and some sexually transmitted infections, as well as respiratory bacterial and viral infections. Vaccinations for influenza, COVID-19, herpes zoster (shingles), hepatitis B, meningococcal disease, mpox, and human papillomavirus are recommended for PWH. Additionally, the Advisory Committee on Immunization Practices has released recommendations incorporating the newer formulations of the pneumococcal pneumonia and respiratory syncytial virus vaccines. Additional considerations for the timing of vaccinations are de-scribed, including whether to delay vaccination until improvement of the immune status. Live vaccines (other than nonreplicating) are contraindicated for PWH with CD4+ counts less than 200 cells/µL or uncontrolled HIV.


Asunto(s)
Infecciones por VIH , Vacunación , Humanos , Infecciones por VIH/prevención & control , Infecciones por VIH/complicaciones , Infecciones por VIH/inmunología , COVID-19/prevención & control , COVID-19/inmunología
2.
HIV Res Clin Pract ; 22(4): 102-118, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34514963

RESUMEN

Background:Understanding the relationship between HIV and SARS-CoV-2 has important public health implications.Objective:To summarize current research on COVID-19 among people with HIV (PWH) as published through 15 July 2021.Methods: We conducted a search of PubMed, Scopus, preprint databases (medRxiv, bioRxiv), and the references of publications found using key terms relevant to COVID-19 ('COVID-19' OR 'SARS-CoV-2' OR 'coronavirus') AND to HIV ('HIV' OR 'Human Immunodeficiency Virus' OR 'AIDS' OR 'Acquired Immunodeficiency Syndrome'). We summarized all articles that reported data or opinions on SARS-CoV-2 and HIV coinfection.Conclusions: Although many initial case series and cohort studies found no increased risk for SARS-CoV-2 infection or severe COVID-19 outcomes among PWH, recent studies have signaled an increased risk for severe COVID-19 disease progression even in the setting of well-controlled HIV. Whether this is due to the increased prevalence of comorbidities in PWH and other social determinants of health is unknown. These conflicting findings highlight the continued need for COVID-19 related research among PWH that addresses COVID-19 disease course as well as exacerbation of existing comorbidities already disproportionately represented among PWH.


Asunto(s)
COVID-19/complicaciones , Infecciones por VIH/complicaciones , Animales , COVID-19/epidemiología , COVID-19/virología , Coinfección/epidemiología , Coinfección/virología , Infecciones por VIH/epidemiología , Infecciones por VIH/virología , VIH-1/genética , VIH-1/fisiología , Humanos , SARS-CoV-2/genética , SARS-CoV-2/fisiología
5.
Open Forum Infect Dis ; 7(9): ofaa354, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33005696

RESUMEN

BACKGROUND: Pneumocystis jirovecii pneumonia (PJP) remains a cause of mortality in HIV-negative patients. The clinical benefit of adjuvant corticosteroids in these patients is uncertain. This study aimed to determine if corticosteroids would reduce mortality in a cohort of HIV-negative PJP patients. METHODS: We examined a retrospective case series of patients diagnosed with PJP at the University of Colorado Hospital between 1995 and 2019. Data were collected in 71 PJP-infected patients. Twenty-eight patients were HIV-negative, and 43 were infected with HIV. We performed bivariate and forward, stepwise multivariable logistic regressions to identify mortality predictors. RESULTS: Common underlying conditions in HIV-negative patients were hematologic malignancies (28.6%), autoimmune disorders (25.9%), and solid organ transplantation (10.7%). HIV-negative patients had higher rates and durations of mechanical ventilation and intensive care unit stay. Survival was significantly increased in HIV-negative patients receiving adjuvant corticosteroids, with 100% mortality in patients not receiving corticosteroids vs 60% mortality in patients receiving corticosteroids (P = .034). In an adjusted multivariable model, no adjuvant corticosteroid use was associated with higher mortality (odds ratio, 13.5; 95% CI, 1.1-158.5; P = .039) regardless of HIV status. CONCLUSIONS: We found substantial mortality among HIV-negative patients with PJP, and adjuvant corticosteroid use was associated with decreased mortality. Response to corticosteroids is best established in HIV-infected patients, but emerging reports suggest a similar beneficial response in PJP patients without HIV infection. Further prospective studies may establish a more definitive role of the addition of corticosteroids among HIV-negative patients with PJP.

6.
J Infect Dis ; 222(Suppl 5): S486-S493, 2020 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-32877543

RESUMEN

In the United States, we are experiencing linked epidemics (a syndemic) of substance use disorders (SUDs) and infections associated with drug use, including unsafe injecting and unsafe sex in exchange for drugs or money. Current drug laws, together with risk-taking behavior among persons with SUDs, contribute to disproportionately high prevalences of these conditions in correctional settings. Detection and treatment of diseases with a high impact on public health are best addressed in the settings where such conditions are most prevalent (ie, jails and prisons for SUDs and chronic infections). The effectiveness, safety, cost of care. and public health impact of these conditions can be improved by means of broader screening and expanded access to specialty consultations through telemedicine/telehealth, along with broader use of long-acting medications for the treatment of human immunodeficiency virus and SUDs. Expanding telemedicine/telehealth, first for specialties which do not require advanced technology (eg, infectious diseases, addictions), can eventually lead to further advancements in correctional healthcare.


Asunto(s)
Infecciones por VIH/tratamiento farmacológico , Epidemia de Opioides/prevención & control , Trastornos Relacionados con Opioides/terapia , Prisiones/organización & administración , Telemedicina/organización & administración , Analgésicos Opioides/efectos adversos , Antivirales/farmacología , Antivirales/uso terapéutico , Enfermedad Crónica/epidemiología , Enfermedad Crónica/terapia , Consumidores de Drogas/psicología , Consumidores de Drogas/estadística & datos numéricos , Infecciones por VIH/diagnóstico , Infecciones por VIH/prevención & control , Infecciones por VIH/transmisión , Accesibilidad a los Servicios de Salud/organización & administración , Humanos , Tamizaje Masivo/organización & administración , Trastornos Relacionados con Opioides/complicaciones , Trastornos Relacionados con Opioides/diagnóstico , Trastornos Relacionados con Opioides/epidemiología , Prevalencia , Prisiones/estadística & datos numéricos , Asunción de Riesgos , Factores de Tiempo , Estados Unidos/epidemiología
7.
Transpl Infect Dis ; 22(3): e13282, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32232951

RESUMEN

Cytomegalovirus (CMV) is a DNA virus of the Herpesviridae family and is estimated to affect 15%-30% of high-risk solid organ transplant recipients. Typical manifestations of CMV end-organ disease in this population include colitis, esophagitis, and pneumonitis, and myocarditis is a rarely reported manifestation. We describe two cases of CMV myocarditis in solid organ transplant recipients and review the literature regarding previously published cases of CMV myocarditis.


Asunto(s)
Infecciones por Citomegalovirus/diagnóstico , Miocarditis/virología , Trasplante de Órganos/efectos adversos , Receptores de Trasplantes , Anciano , Antivirales/uso terapéutico , Infecciones por Citomegalovirus/complicaciones , Infecciones por Citomegalovirus/tratamiento farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Miocarditis/diagnóstico
8.
Am J Trop Med Hyg ; 102(6): 1189-1190, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32329432

RESUMEN

Public health measures are needed to resolve the novel coronavirus disease (COVID-19) pandemic, although a looming economic fallout merits close attention. Early safe reintroduction of immune individuals into the workforce may be essential to protecting the economic welfare of communities. Reverse transcriptase-polymerase chain reaction testing, our primary diagnostic tool to date, has sensitivity and timing concerns, owing to sampling/handling errors, as well as a complex virus-host interaction. Reverse transcriptase-polymerase chain reaction assays do not establish immune status once the virus has been cleared. Targeted serosurveillance for the determination of individuals' potential for transmissibility, particularly if paired with direct pathogen testing, may aid in "cleared for business" decision-making.


Asunto(s)
Anticuerpos Antivirales/sangre , Betacoronavirus/patogenicidad , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/epidemiología , Pandemias , Neumonía Viral/diagnóstico , Neumonía Viral/epidemiología , ARN Viral/genética , Betacoronavirus/genética , Betacoronavirus/inmunología , COVID-19 , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Interacciones Huésped-Patógeno/inmunología , Humanos , Inmunidad Humoral , Inmunoensayo/normas , Vigilancia Inmunológica , Neumonía Viral/inmunología , Neumonía Viral/virología , Cuarentena/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/normas , SARS-CoV-2 , Estados Unidos/epidemiología
9.
Emerg Infect Dis ; 26(2): 383-385, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31961310

RESUMEN

In North America, hantaviruses commonly cause hantavirus pulmonary syndrome (HPS). Clinical descriptions of hantavirus-associated renal disease in the Americas are scarce. Herein, we discuss the case of a 61-year-old man whose predominant manifestations were acute kidney injury and proteinuria. Clinical recognition of renal signs in hantavirus infections can reduce risk for death.


Asunto(s)
Síndrome Pulmonar por Hantavirus/diagnóstico , Orthohantavirus/aislamiento & purificación , Insuficiencia Renal/diagnóstico , Colorado , Diagnóstico Diferencial , Síndrome Pulmonar por Hantavirus/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Proteinuria/etiología , Insuficiencia Renal/complicaciones
10.
Telemed J E Health ; 26(6): 776-783, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31486710

RESUMEN

Introduction: The United States has the largest correctional population in the world and many inmates lack access to timely health care. Studies have shown that telemedicine could improve the situation in a practical and cost-effective fashion. We aimed to evaluate currently established services as well as any potential need for expansion of telemedicine within correctional settings in Colorado. Methods: We designed a prospective survey-based pilot study using mixed methods research techniques. Results: Colorado has 50 county jails, 19 prisons, and 3 private prison facilities. Of these, 46 correctional facilities (45 jails and the state prison) were contacted. Twenty responded (19 jails and the prison) representing 43.5% response rate. Only 10% did not have on-site health care providers available at all, 31.6% were already using telemedicine for some of their needs, 52.9% were "very interested," 5.9% "somewhat interested," 17.6% "not so interested," and 23.5% were "not at all interested" in further information regarding telemedicine services. Discussion: Our study as well as current literature suggest that telemedicine could serve to fill in certain gaps of care within correctional populations, especially for over-represented conditions (i.e., chronic infectious diseases, such as HIV and hepatitis C virus, substance use disorders, or mental health disorders). Conclusions: There is enthusiasm but also certain amount of skepticism among Colorado's jail administrators with respect to the implementation, or even the cost-effectiveness potential of telemedicine. Telemedicine in these settings may require individualized approach and enough creative flexibility to allow for nimble adjustments based on the constraints and needs of individual institutions.


Asunto(s)
Prisioneros , Telemedicina , Colorado , Atención a la Salud , Humanos , Proyectos Piloto , Prisiones , Estudios Prospectivos , Estados Unidos
12.
Top Antivir Med ; 28(3): 465-468, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-34107205

RESUMEN

Vaccines play an important role in HIV primary care and are available for several sexually transmitted infections, including those caused by hepatitis A virus (HAV), hepatitis B virus (HBV), and human papillomavirus (HPV). HAV vaccination is increasingly important, given recent hepatitis A outbreaks and lack of immunity in many adults. A novel formulation of the hepatitis B vaccine shows promise in increasing rates of seroprotection. The Advisory Committee on Immunization Practices recommends the meningococcal conjugate vaccine for all individuals with HIV and has expanded the age range for administration of the HPV vaccine, recommending shared decision making about its administration in adults aged 27 to 45 years. This article summarizes a presentation by Steven C. Johnson, MD, at the International Antiviral Society-USA (IAS-USA) annual continuing education program held in New York, New York, in September 2019.


Asunto(s)
Infecciones por VIH/prevención & control , Vacunación , Adulto , Comités Consultivos , Infecciones por VIH/transmisión , Hepatitis A , Vacunas contra Hepatitis B/administración & dosificación , Humanos , Vacunas Meningococicas/administración & dosificación , Persona de Mediana Edad , New York , Vacunas contra Papillomavirus/administración & dosificación
13.
AIDS Res Hum Retroviruses ; 35(11-12): 1082-1088, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31432692

RESUMEN

Mortality for people living with HIV (PLWH) has dramatically decreased since the mid-1990s and the proportion of deaths attributable to non-AIDS-related conditions has increased. Deceased PLWH were identified from a single academic medical center through provider survey and electronic medical record query. Cause of death was determined using the Coding Causes of Death in HIV tool following review of available medical records. Chart review of comorbidities, demographics, laboratory values, and previous completion of screening tests for malignancies was conducted for deaths during the period of 2013-2017. The proportion of AIDS-related deaths decreased markedly between 1995 and 2017, while the proportion of deaths from non-AIDS malignancies increased. From 2013 to 2017, 30 of 121 deaths were attributed to AIDS-related conditions, 32 to non-AIDS malignancies, 14 to suicide/homicide or sudden death, 10 to cardiac causes, 28 to other non-HIV causes, and 7 to unknown causes. Those who died of non-AIDS-related malignancies were older than AIDS-related deaths [mean age 55.8 (7.6) vs. 47.3 (13.5), p value = .003]. Less than half of potentially eligible patients had documented colon cancer screening. The number of individuals dying from AIDS-related conditions has decreased significantly and non-AIDS-related causes, particularly non-AIDS-related malignancies, have become more prominent causes of death. As our patients age, a greater focus needs to be placed on management of comorbid illnesses and screening and prevention of malignancy.


Asunto(s)
Centros Médicos Académicos/estadística & datos numéricos , Síndrome de Inmunodeficiencia Adquirida/mortalidad , Infecciones por VIH/mortalidad , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Adulto , Terapia Antirretroviral Altamente Activa , Causas de Muerte , Comorbilidad , Femenino , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/mortalidad , Estudios Retrospectivos
14.
Top Antivir Med ; 23(5): 161-7, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27398769

RESUMEN

Antiretroviral therapy is recommended for all patients with HIV infection. The benefit of immediate antiretroviral therapy was confirmed by results from the START (Strategic Timing of Antiretroviral Treatment) trial, which showed a 57% reduction in risk for the composite end point of AIDS-related events, serious non-AIDS-related events, or death from any cause with immediate treatment in antiretroviral therapy-naive participants with CD4+ cell counts above 500/µL. Other changes in HIV care include the widespread adoption of integrase strand transfer inhibitor-based regimens. Considerations regarding when to initiate antiretroviral therapy, which initial regimens to use, and appropriate monitoring of individuals taking antiretroviral therapy are discussed. This article summarizes an IAS-USA continuing education webinar presented by Steven C. Johnson, MD, in July 2015.


Asunto(s)
Antirretrovirales/uso terapéutico , Terapia Antirretroviral Altamente Activa/métodos , Monitoreo de Drogas , Infecciones por VIH/tratamiento farmacológico , Humanos , Factores de Tiempo
15.
AIDS Patient Care STDS ; 28(9): 475-82, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25084559

RESUMEN

Initial descriptions of the HIV engagement continuum are limited by short-term follow-up and incomplete data. We evaluated engagement in a newly HIV-diagnosed cohort. Our goals were to assess long-term engagement-in-care, evaluate the effects of out-of-state migration on engagement estimates, and determine whether engagement has improved in more recently diagnosed individuals. This is a retrospective cohort study of individuals newly HIV-diagnosed at two large HIV care centers in the Denver metropolitan area from 2005 to 2009. Clinical data were obtained from three public HIV providers and two clinical trial groups. For statewide evaluation, we used mandated laboratory reporting databases for CD4 lymphocyte counts and HIV-1 RNA levels. From 2005 to 2009, 615 individuals were diagnosed with HIV. By 18 months after HIV diagnosis, 84% of the cohort had linked to care, 73% were retained in care, 49% were prescribed antiretroviral therapy, and 36% had viral suppression. By 5 years after HIV diagnosis, 55% of the cohort were retained in care, 37% had viral suppression, 15% had moved out of state, and 3% were deceased. When censoring for outmigration and death, 66% of the cohort were retained in care and 45% of the cohort had viral suppression 5 years after HIV diagnosis. Engagement-in-care 18 months after diagnosis was better in individuals diagnosed more recently. Retention in care declined while viral suppression increased over time after HIV diagnosis. Accounting for outmigration and death significantly increased estimates of engagement-in-care. Performance in the engagement continuum 18 months after diagnosis improved significantly in individuals more recently diagnosed with HIV.


Asunto(s)
Antirretrovirales/uso terapéutico , Continuidad de la Atención al Paciente , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Cooperación del Paciente/estadística & datos numéricos , Carga Viral/estadística & datos numéricos , Adulto , Recuento de Linfocito CD4 , Colorado/epidemiología , Atención a la Salud , Ensayo de Inmunoadsorción Enzimática , Femenino , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , Humanos , Masculino , Vigilancia de la Población , Estudios Retrospectivos , Factores de Riesgo , Factores Socioeconómicos , Factores de Tiempo , Resultado del Tratamiento
16.
Neurol Clin Pract ; 4(2): 114-122, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27606153

RESUMEN

Syphilis is a sexually transmitted infection caused by Treponema pallidum. A total of 13,106 cases of primary and secondary syphilis were reported in the United States in 2011 and the rate of infection has increased in subgroups, particularly men who have sex with men. The disease is mainly diagnosed through clinical findings and serologic testing. However, no single serologic test of syphilis is sufficient. Hence, the serologic diagnosis of syphilis requires the detection of 2 types of antibodies (nontreponemal antibodies and treponemal antibodies). The paradigm in syphilis testing has recently shifted in many centers to screen with a treponemal antibody test, reflexing to a nontreponemal test if the treponemal antibody test is positive. This reverse of the traditional algorithm may not be widely recognized among clinicians.

17.
J Int Assoc Provid AIDS Care ; 12(6): 384-90, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23962912

RESUMEN

This is a retrospective cohort study of 352 newly diagnosed HIV-infected individuals in Denver, from 2005 to 2007. Utilizing data from 3 health care systems, 2 clinical trials units, and statewide Colorado HIV laboratory reporting databases, we tracked initial linkage to HIV care, retention in care, loss to follow-up, and transitions between HIV care providers. After more than 2.6 years of follow-up, 256 (73%) individuals linked to HIV care within 180 days. Of the 301 individuals who eventually linked to care, 168 (56%) had at least one 180-day gap in care, while 49 (16%) had a 360-day gap. Transitions in care were common, with 131 (37%) individuals accessing care from 2 different providers and 15% having evidence of living outside of Colorado. In this newly diagnosed HIV-infected cohort, linkage to care was slow and long-term retention in care was poor. Transitions between HIV care providers were common and may impair engagement in care over time. Out-of-state migration was frequent and may cause an underestimation of engagement in care.


Asunto(s)
Infecciones por VIH/terapia , Adulto , Colorado , Atención a la Salud , Femenino , Infecciones por VIH/diagnóstico , Humanos , Perdida de Seguimiento , Masculino , Tamizaje Masivo , Salud Pública , Estudios Retrospectivos
18.
J Immigr Minor Health ; 15(4): 667-72, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22562621

RESUMEN

To compare foreign-born (FB) and US-born (USB) patients (pts) in a US HIV care program. Retrospective review. Data were collected on all FB and a random sample of 5 % of USB pts in an HIV clinic in Colorado, USA. Comparisons were made between FB pts and USB pts and among FB pts by global region of origin and sex. Among 150 FB and 59 USB pts, FB pts were younger (40 vs. 45 years), proportionately more female (39 vs. 17 %), with heterosexual sex as HIV risk factor (69 vs. 23 %) and reported substance use less (6 vs. 38 %) (All p ≤ 0.001) compared to USB pts. Age and substance differences persisted between FB and USB women. Significant differences also existed between FB and USB pts in reason for HIV test, tuberculosis and mental health diagnoses, and diagnosis of >1 co-morbidity, but not in mean CD4 cell count (502 vs. 569), antiretroviral therapy (ART) (92 vs. 90 %), or alcohol use (29 vs. 37 %). Compared to FB women, FB men were more commonly men that have sex with men, from Latin America/Caribbean, have HIV testing for illness, and have had a concomitant HIV and AIDS diagnosis while FB women were more commonly refugees, heterosexual and from Africa. Differences exist between FB and USB HIV-infected pts, and among FB pts themselves. HIV care and prevention programs must recognize and address these dissimilarities in order to maximize clinical outcomes, improve linkage to and continuity in care and optimize resource allocation.


Asunto(s)
Infecciones por VIH/etnología , Características de la Residencia , Conducta Sexual , Adulto , Factores de Edad , Antirretrovirales/uso terapéutico , Comorbilidad , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/terapia , Humanos , Masculino , Persona de Mediana Edad , Refugiados/estadística & datos numéricos , Estudios Retrospectivos , Factores de Riesgo , Trastornos Relacionados con Sustancias/epidemiología , Estados Unidos/epidemiología
19.
J Pharm Pract ; 26(4): 397-400, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23204147

RESUMEN

Tenofovir disoproxil fumarate (TDF), a nucleotide reverse transcriptase inhibitor used in the treatment of human immunodeficiency virus (HIV) and hepatitis B, is renally eliminated and has been associated with renal toxicities. Dose adjustments are recommended for patients with creatinine clearance (CrCL) <50 mL/min. We retrospectively determined the frequency in which HIV clinic providers adjusted TDF doses in patients with CrCL <50 mL/min over a 2-year period and compared clinical outcomes in patients who had TDF dose adjustments based on CrCL <50 mL/min versus those who did not. Thirty-nine patients with CrCL <50 mL/min were identified. Dose-adjusted patients (N = 9) continued their TDF-based antiretroviral regimens for 21 months longer following the first CrCL < 50 mL/min (P = .0193) and had gains in CD4 cell counts over 12 months (P = .0009). There were no statistically significant differences in CrCL or percentage of patients with detectable HIV-1 RNA at 6 and 12 months following first CrCL <50 mL/min in those who did versus did not have a TDF dose adjustment. In summary, HIV providers often failed to dose-adjust TDF in patients with CrCL <50 mL/min, but dose-adjusted patients appeared to stay on their TDF-based regimens longer and have greater gains in CD4 cells. Larger, prospective studies are needed to validate these results.


Asunto(s)
Adenina/análogos & derivados , Fármacos Anti-VIH/efectos adversos , Riñón/efectos de los fármacos , Ácidos Fosforosos/efectos adversos , Adenina/administración & dosificación , Adenina/efectos adversos , Adulto , Creatinina/sangre , Femenino , Humanos , Riñón/fisiología , Masculino , Persona de Mediana Edad , Ácidos Fosforosos/administración & dosificación , Estudios Retrospectivos
20.
Protein Expr Purif ; 84(2): 247-54, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22705766

RESUMEN

Supplementation of animal feed with phytases has proven to be an effective strategy to alleviate phosphorous contamination of soil and water bodies. The inability of non-ruminant animals to digest phytates in corn and soybeans contributes to environmental contamination. Alkaline phytase from lily pollen (LlALP) exhibits unique catalytic and thermal stability properties that could be useful as a feed supplement. rLlALP2 was successfully expressed in Pichia pastoris; however, enzyme yields were modest (8-10 mg/L). In this paper, we describe our efforts to enhance rLlALP2 yield by investigating the influence of the following potential limiting factors: transgene copy number, codon bias, sequence optimization, and temperature during expression. Data presented indicate that increasing rLlAlp2 copy number was detrimental to heterologous expression, clones with one copy of wt-rLlAlp2 produced the highest activity, clones with two, four and seven or more copies produced 70%, 25% and 10% respectively, of enzyme activity implying that gene dosage is not limiting rLlALP2 yield. Use of a sequence-optimized rLlAlp2 increased the yield of the active enzyme by 25-50% in one/two copy clones, suggesting that translational efficiency is not a major bottleneck for rLlALP2 expression. Reducing the temperature during heterologous expression led to increases of 1.2-20-fold suggesting that protein folding and post-translational processes may be the dominant factors limiting rLlALP2 expression. Early knowledge of the transgene copy number allowed us to develop a more rational strategy for yield enhancement. Cumulatively, sequence optimization and temperature reduction led to the doubling of rLlALP2 enzyme activity in P. pastoris.


Asunto(s)
6-Fitasa/genética , Clonación Molecular , Lilium/enzimología , Lilium/genética , Pichia/genética , 6-Fitasa/química , 6-Fitasa/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular/métodos , Dosificación de Gen , Expresión Génica , Lilium/química , Datos de Secuencia Molecular , Pichia/metabolismo , Plásmidos/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Temperatura
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